Ornamented leather and method of making the same



May 28, 19.35. c, D, SART I 2,002,792

' ORNAMENTED LEATHER AND METHOD OF MAKING THE SAME Filed April 26, 1935 Patented May 28, 1935 UNITED STATES PATENT O FFI CE ORNAMENTED LEATHER AND DIETHOD OF MAKING THE SALE Application April 26, 1935, Serial No. 18,274

13Claims.

This application is a continuation in part of my application Ser. No. 734,223, filed July '7, 1934. The invention relates to ornamented leather and method of making the same.

It is an object of the invention to produce a leather having portions of the grain surface slightly raised to form a design set off by depressed portions from which the grain surface has been removed these depressed portions thus having a suede or flesh surface. It is a further object of the invention to provide a leather of the kind described, which is dyed in such a manner as to produce good color depth, especially in the suede areas, the color of which may, if desired, contrast with the color of the grain areas.

Other advantageous features of the invention will be apparent to one skilled in the art from the disclosure thereof in the following description and, from the illustration thereof on the drawing, of which Figure 1 is a perspective view of a piece of leather having a diamond pattern produced according to the invention.

Figure 2 is a perspective view of a piece of leather having an arbitrary design produced in the same manner.

Figure 3 is a fragmentary view of a piece of leather and pressing mechanism for embossing a design on the grain face thereof.

Figure 4 is a fragmentary sectional view of a piece of embossed leather, a portion of the grain face of which has been buffed off.

Figure 5 shows in section a piece of leather which has been embossed, buffed, and then soaked to raise the depressed portions above the bufied portions.

In practicing the invention, I preferably employ a full grain skin such as calf skin. The skin is placed on a flat plate I, flesh side down, and a suitable pattern is embossed on the grain surface H as by a die I! which is 'pressed against the grain face ll so that portions thereof are indented as at l3. The embossed face of the leather is then buffed on an abrasive wheel in a manner well known in the art so that the elevated portions l5 of the grain surface II are ground off, leaving the depressed grain surfaces I3 and buffed or suede surfaces IS.

The buffed leather is then subjected to a water bath, preferably at a temperature of about and in a color drum where the. leather can be suitably agitated. The water serves to soften the leather and to restore the pressed portions to their natural density. Since portions of the grain surface have been bullied oil as at I, these areas will then be below the grain surface areas l3, as indicated in Figure 5. Thus the embossed pattern is reversed, the areas originally raised by the embossing press being now lower than the originally depressed areas.

The bath employed to restore the pressed portions of the leather to their original density, may

' evenly. If desired, a suitable quanity of one of these alkalis may be mixed with an acid or direct dye bath for the same purpose.

After the leather has been prepared by soaking and agitation, as described, a dyeing bath may be introduced into the color drum after the soaking bath has been drained off. According to my invention, I have discovered that the patterns formed by the grain and suede areas on the grain face of the leather can be accentuated in varying degrees and the depth of color tones can be closely controlled by the use of certain kinds or classes of dyes which have different selective effects on the grain and suede areas respectively and can be combined to control the variations of color and tone contrasts and depths of shades, so that the color and tones of samples can be accurately reproduced. To this end I may employ acid dyes (such as acid orange 11 or resorcine brown R) which take hold on both grain and suede surfaces efficiently so that the dyes of this group can be used in relatively low concentrations, with resulting economy. Acid dyes take hold on original surfaces of leather (e. g. chrome tanned leather) somewhat better than on surfaces exposed by cutting or abrading below the original surface, due to the fact that the surfaces of the leather as it comes from the tanning process contain certain oily substances employed for softening and finishing the leather. Acid dyes take hold better where an oil is present, so that when used for coloring leather the original surfaces of the leather are darker than suede areas where the interior has been exposed by removal of portions of the grain surface.

Direct dyes (such as direct black E or leather brown TD") take hold strongly on flesh surfaces, but take hold very gradually on grain surfaces, so that maximum contrasts of tones can be ob tained when direct dyes'only are used. This is due to the strong chemical affinity for dyes of this class possessed by chemicals left in the interior of the leather by the tanning process in comparison with the surface of the leather which dy takes direct dyes very slowly. As herein employed, the term direct dyes refers to the usual classification of dyes based on the mode of their application in dyeing, and is intended to mean coal tar dyes, commonly employed for textiles, which take hold of cotton fibers directly, that is, without the aid of mordants. This class of dyes includes some dyes which are acid dyes according to a strict chemical classification but does not include developed dyes or colors, that is, colors which must be precipitated or produced on the fibers by the successive application to the fiber of the constituent elements of the color.

Acid dyes and direct dyes may be mixed in the dyeing bath, in which case the effect on the leather is the sum of the individual effects of the two dyes acting independently. When the leather is dyed with such a mixture, the color of the acid dye usually predominates on the grain surface areas whilst the color of the direct dye takes hold chiefly on the suede areas, its color being added to that of the acid dye on the suede areas. This results in a color contrast in addition to or instead of a tone contrast in a single color.

Basic dyes (such as nigeria black GX", basic brown Br, or phosphone D) take hold better on the suede areas than on the grain areas, though the contrast is not as pronounced as in the case of direct dyes. While I may employ a basic dye alone in coloring embossed and buifed leather, such dyes are used to best advantage after the skin has previously been dyed with an acid and/or direct dye. The usual effect of the basic dye is to modify and deepen the colors previously received by the skin and to tone down to some extent the contrast between the grain and suede areas.

The variations of tone and color contrast produced by selection of dyes can be further controlled and modified by selective partial discharge of the colors through the use of suitable substances such as sodium hyposulphite. This may be employed to discharge a portion of the dye, especially on the grain parts. This serves to intensity the contrasting efiect between the suede areas and the grain areas. The leather is then given a final wash, after which it is further treated after a manner well known in the art. Such further treatment may comprise treating with fat liquor to condition the; skins, whereupon they are removed from the drum and are hung up to dry. After drying, they are rolled in damp sawdust, stretched, dry milled and tacked on frames.

It is evident that various modifications and changes may be made in the specific embodiments of the invention hereinbefore set forth without departing from the spirit or scope thereof as defined in the following claims.

I claim:

1. A method of treating leather, which comprises embossing a design on the grain side, buffing off the raised portions of the grain surface, and submerging the leather in a bath of mixed acid and direct dyes.

2, A method of treating leather, which comprises embossing a design on the grain side, bufilng off the raised portions of the grain surface, immersing the leather in an acid dye, washing and subsequently treating the leather with a basic 3. A method of treating leather, which comprises embossing a design on the grain side, bufilng off the raised portions of the grain surface, treating the leather with an acid dye, washing the leather, treating the leather with a basic dye, washing again, treating with sodium hyposulphite solution, and giving the leather a final wash.

4. A method of treating leather, which comprises embossing a design on the grain side, bufllng off the raised portions of the grain surface, soaking the leather in a solution of disodium phosphate, treating the leather with an acid dye bath, and washing.

5. A method of treating leather, which comprises embossing a design on the grain side, butting off the raised portions of the grain surface, soaking the leather in a solution of disodium phosphate, treating the leather with an acid dye bath, washing, treating with a basic dye bath, and washing again.

6. A method of treating leather, which comprises pressing the leather to emboss a design on the grain side, bufilng ofi the raised portions of the grain surface, and treating the bufled leather to the following baths: solution of disodium phosphate, mixed acid dye and direct dye, wash, basic dye, wash, solution of sodium hyposulphite, and wash.

'7. A method of treating leather, which comprises embossing a design on the grain side, bufilng off the raised portions of the grain surface to form suede areas forming a pattern with the residual grain areas, and dyeing the leather with dyes capable of producing different colors-on said grain and suede areas respectively.

8. A method of treating leather, which comprises embossing a design on the grain side, bumng off the raised portions of the grain surface, agitating the buffed leather in a liquid bath, and dyeing the leather with an acid dye.

9. A method of treating leather, which comprises embossing a design on the grain side, bufilng off the raised portions to form suede areas on the grain side, and dyeing said leather with a dye which has a selective aflinity for the interior of the leather.

10. A method of treating leather, which comprises embossing a design on the grain side, bufl'lng off the raised portions of the grain surface, agitating the bufied leather in a liquid bath, and dyeing the leather with a direct dye.

11. A method of treating leather, which comprises embossing a design on the grain side, bumng off the raised portions to form suede areas on the grain side, and dyeing said leather with a dye selected from a group consisting of acid and direct dyes.

12. ornamented dyed leather characterized by suede areas of one color on the grain side and.

-grain areas of a dlfierent color contrasting with the suede areas to form a pattern.

13. Ornamented leather characterized by areas of suede finish on the grain face contrasting with the residual grain areas to form a pattern, the entire surface of the leather being colored with an acid and a direct dye.

' GILBERT D. SART. 

